Fast, accurate and reliable measurement of CH4. The extraction of coal releases methane gas, which can mix with the air in a mine to form a hazard due to its flammability. Ventilation with fresh air from the surface is used to dilute the methane and reduce the risk of explosion. Monitoring of the methane content of the stale air exiting the mine allows the amount of ventilation to be controlled. Although our sensors are not ATEX approved for use in potentially explosive atmospheres they are suitable for monitoring air containing methane concentrations below the lower explosive limit. Our OEM products can be built into equipment which is approved for use in the monitoring of mine exhaust gas and similar applications.